Method and System for Diagnosing Radio Performance During Functional Over-The-Air Operation

1. An apparatus for determining a health of a mobile radio-frequency transmitter, the apparatus comprising: a receiver for receiving a received signal responsive to a transmitted signal transmitted from the mobile transmitter, the transmitted signal transmitted during normal over-the-air operation of the mobile transmitter and not having known signal characteristics; a first element for determining a first signal parameters value of the received signal, the first signal parameter value responsive to signal power of the received signal; the first element for determining additional signal parameter values of the received signal; the transmitted signal and the received signal each including an identifier of the mobile transmitter, the identifier for linking the first signal parameter value and the additional signal parameter values with the mobile transmitter; and a second element for determining whether the first signal parameter value exceeds a predetermined value; if the first signal parameter value exceeds the predetermined value, the second element for determining a health of the mobile transmitter, the health responsive to a relationship between one or more of the additional signal parameter values and a respective specification value or a range of respective specification values for each one of the additional signal parameter values, wherein the respective specification value or the range of respective specification values are independent of distance and link quality between the mobile transmitter and the receiver.

2. The apparatus of claim 1 wherein the first signal parameter comprises a signal strength related parameter.

3. The apparatus of claim 2 wherein the signal strength signal related parameter is responsive to a location of the transmitter relative to a location of the receiver.

4. The apparatus of claim 2 wherein the signal strength related parameter comprises RSSI, SNR, received signal power, or another power-related parameter.

5. The apparatus of claim 1 wherein the receiver is disposed onboard a moving vehicle or is disposed at a fixed location.

6. The apparatus of claim 1 wherein the additional signal parameter values comprise frequency-related signal parameter values of the transmitted signal.

7. The apparatus of claim 6 wherein the frequency-related signal parameter values comprise one or more of RF frequency accuracy, RF frequency offset, timing of RF frequency offsets relative to a beginning of a message, RF frequency deviations throughout a message, frequency deviation of a modulated signal, a range of frequency deviations over time, maximum frequency deviation.

8. The apparatus of claim 1 wherein the health comprises one of a failed transmitter, a suspect transmitter, and a good transmitter.

9. The apparatus of claim 1 wherein the additional signal parameter values for a first group of additional signal parameters are determined more frequently than additional signal parameter values for a second group of additional signal parameters.

10. The apparatus of claim 1 wherein the additional signal parameters values comprise one or more of amplitude variations during a message transmission, symbol frequency error, symbol clock error, modulation fidelity, bit error rate, conformance to packet structure specifications, baud rate changes during a message transmission, spurious emissions, consistent low power level irrespective of location of the transmitting device, high bit error rate irrespective of location of the transmitting device, battery charge, and a number of retries over a predetermined threshold.

11. The apparatus of claim 1 configured with a storage time parameter for identifying a period of time for storing the first and the additional signal parameter values and configured with a data collection frequency parameter for identifying a frequency at which the first and the additional signal parameter values are determined.

12. The apparatus of claim 1 wherein the mobile transmitter comprises a transmitter operating in a trunked radio network, and wherein the received signal comprises at least one of a request from the mobile transmitter to a network controller for an inbound channel and an inbound channel carrying transmissions from the mobile transmitter.

13. The apparatus of claim 1 operating in conjunction with a location-determining system for determining a location of the mobile transmitter in a trunked radio network, and wherein one or more of the first or the additional signal parameter values of a signal transmitted by the mobile transmitter must satisfy a predetermined threshold before the location-determining system determines a location of the mobile transmitter.

14. The apparatus of claim 1 wherein the identifier comprises a radio identifier or a diagnostic identifier.

15. The apparatus of claim 1 wherein the frequency of determining the first and the additional signal parameter values is user-defined for each mobile transmitter.

16. The apparatus of claim 1 further comprising a component for issuing email alerts identifying failed or suspect mobile transmitters.

17. The apparatus of claim 1 wherein the second element determines whether the received signal is compliant with applicable signal packet specifications.

18. The apparatus of claim 1 wherein the receiver is collocated with a base station of a network or the receiver comprises an element of the base station.

19. A method for determining a health of a radio-frequency (RF) transmitting device, the method comprising: at a receiver, receiving an RF signal transmitted from an RF transmitting device, the transmitted signal transmitted during normal over-the-air operation of the RF transmitting device and not having known signal characteristics; measuring a first signal parameter value related to signal power and measuring additional signal parameter values of a received RF signal, the received RF signal responsive to the transmitted signal; determining whether the first signal parameter value exceeds a threshold value for the first signal parameter value; determining a health of the RF transmitting device responsive to the additional signal parameter values only when the first signal parameter value exceeds the threshold value, wherein the health is responsive to a relationship between each one of the additional parameter values and a respective specification value for each one of the additional signal parameter values, wherein the specification values are independent of distance and link quality between the transmitting device and the receiver; and wherein the received RF signal includes an identifier of the RF transmitting device, using the identifier to link a health determination with the RF transmitting device.